1. Field of the Invention
The present invention relates to improvements in the field of bulk shipping. More particularly, the invention pertains to a method and apparatus for palletizing peat moss in bulk compressed form as well as to the palletized peat moss obtained thereby.
2. Description of Prior Art
Owing to its unique porous structure, peat moss can absorb from about 8 to about 20 times its weight in water. Such a high absorption capacity renders peat moss particularly suitable for use in absorbent products such as diapers, sanitary napkins, tampons and the like. For example, in U.S. Pat. No. 4,507,122, a low density peat moss board is formed from a slurry of screened peat moss in admixture with mechanical wood pulp. The board is used as a central core in body fluid absorbing products.
Peat moss is also widely used in horticulture as soil adduct, compost, culture base, etc. As described in U.S. Pat. No. 3,883,989, expandable shape-retaining peat moss briquettes suitable for growing plants can be produced by intermixing an aqueous bituminous emulsion with peat moss in critical proportions of peat moss to bitumen, drying the mixture and compressing individual portions of the dried mix uni-directionally to form rigid bodies. These bodies are expanded by contact with water to form soft, moist, shape-retaining cakes for growing plants therein. French Patent No. 2,099,177, on the other hand, describes a synthetic soil substrate made from compressed peat moss/vermiculite mixtures. A mixture of exfoliated vermiculite and peat moss in critical ratios of vermiculite to peat moss is compressed to 1/3 to 1/20 of its original volume to form pellets. These pellets may be used in containers where they are expanded by the addition of water to form a very active plant soil especially suitable for potted plants and seedlings.
In view of its multiple usage, peat moss is shipped throughout the world from major peat-bogs located predominantly in USSR and Canada. Peat moss is generally packaged under compression into plastic bags for shipment. A typical apparatus for packaging peat moss into bags is described in Canadian Patent No. 1,043,310. The volume of a bag filled with compressed peat moss is usually not larger than about 0.17 cubic meter in order to facilitate handling and shipping. Thus, a single shipment of peat moss may comprise thousands of such bags. The quantity of plastic bags utilized for packaging, and discarded after use, is of course phenomenal and represents a serious threat to the environment. On the other hand, bulk shipping of peat moss in large containers must be effected rapidly since a prolonged exposure of peat moss to atmospheric oxygen causes a bacterial decomposition of the peat moss.